A triangle whose sides are 5,12, and 13 inches are similar to a triangle whose longest side is 39 inches. What is the perimeter of the larger triangle

90

Step-by-step explanation:

If the triangles sides are 5,12, and 13

5+12+13=30

next if the longest side of the larger triangle is 39 then this means that the longest side of the smaller triangle has to be somehow related to 39 so you can do division and that would look like this:

39:13=3

so with this answer you can say if the largest side of the smaller triangle multiplied by 3 then all of the other sides have to multiply by 3. thus making the equation

(5*3) + (12*3) + (13*3) = 90

and your final answer is 90